The invention relates to pile weatherstrip and to methods for the manufacture of pile weatherstrip.
Pile weatherstrip commonly comprises an elongate base strip carrying a pile of thermoplastic fibres, such as polypropylene fibres. The fibres extend across the strip and along the strip but the width of the pile is not as great as the width of the strip so that the strip extends to either side of the pile.
In use, the pile weatherstrip is held by a channel-section carrier which has a base, upstanding side walls and inwardly directed flanges at the ends of the side walls. The width of the base is generally the width of the base strip and the gap between the ends of the flanges is generally the width of the pile. Thus, as the base strip is slid into the channel, the edges of the base strip are held between the flanges and the base, while the pile projects through the gap between the flanges.
In general, such a weatherstrip can be inserted easily into such a channel by inserting one of the strip into one end of the channel and pushing the strip along the channel. It has been found, however, that particularly where the channel is of substantial length and is made of aluminium or plastics materials. It can be difficult to insert a pile weatherstrip into such a channel. It is believed that this is because individual fibres catch on the free ends of the flanges that define the gap through which the pile passes and this resists the insertion of the weatherstrip.
According to a first aspect of the invention there is provided a pile weatherstrip comprising an elongate base strip having spaced side edges and carrying a pile of thermoplastic fibres, the fibres extending across the strip and along the strip, with the pile having side edges spaced inwardly of the associated side edges of the base strip, at least the fibres at the side edges being fused together along the length of the weatherstrip and for at least a portion of the height thereof adjacent the base strip.
This fused zone is thus the zone adjacent the free ends of the flanges when the pile weatherstrip is inserted into a channel, The fusing ensures that the fibres do not catch on the free ends of the flanges during such insertion so making easier the insertion of such a weatherstrip into a long length of channel.
According to a second aspect of the invention there is provided a method of manufacturing a pile weatherstrip comprising forming a pile of thermoplastic fibres on an elongated base strip having side edges with the fibres extending across the strip and along the strip and with the pile having side edges spaced inwardly of the respective adjacent side edges of the pile, and then fusing together along the length of the pile at least the thermoplastic fibres at the side edges of the pile for at least a portion of the height thereof adjacent the base strip.